At first "an excavation," later (late 15c.) applied to the resulting earth mound; a sense development paralleled by cognate forms in many other languages. This is the northern variant of the word that in the south of England yielded ditch (n.).

1560s, "to bring a building to ruin," from Latin dilapidatus, past participle of dilapidare "to squander, waste," originally "to throw stones, scatter like stones;" see dilapidation. Perhaps the English word is a back-formation from dilapidation.

1520s, from Late Latin dilemma, from Greek dilemma "double proposition," a technical term in rhetoric, from di- "two" + lemma "premise, anything received or taken," from root of lambanein "to take" (see analemma). It should be used only of situations where someone is forced to choose between two alternatives, both unfavorable to him. But even logicians disagree on whether certain situations are dilemmas or mere syllogisms.

1733, borrowing of Italian dilettante "lover of music or painting," from dilettare "to delight," from Latin delectare (see delight (n.)). Originally without negative connotation, "devoted amateur," the pejorative sense emerged late 18c. by contrast with professional.

Sense evolved from "love" through "attentiveness" to "carefulness" to "steady effort." From the secondary French sense comes the old useage of diligence for "public stage coach" (1742; dilly for short), from a French shortening of carrosse de diligence.

"delightful or excellent person or thing" (often used ironically), 1935, American English, from an earlier adjective (1909), perhaps from the first syllable of delightful or delicious, or related to the nursery word for "duck." Dilly was also slang for a stagecoach (1818), from French carrosse de diligence (see diligence).

Old English dimm "dark, gloomy, obscure," from Proto-Germanic *dimbaz (cognates: Old Norse dimmr, Old Frisian dim, Old High German timber "dark, black, somber"). Not known outside Germanic. Slang sense of "stupid" is from 1892. Related: Dimly; dimness.

The verb meaning "to inform" (on someone) is 1960s, from the then-cost of a pay phone call. A dime a dozen "almost worthless" first recorded 1930. Phrase stop on a dime attested by 1954 (a dime being the physically smallest unit of U.S. currency).

early 15c., from merger of two obsolete verbs, diminue and minish. Diminue is from Old French diminuer "make small," from Latin diminuere "break into small pieces," variant of deminuere "lessen, diminish," from de- "completely" + minuere "make small" (see minus).

Minish is from Old French menuisier, from Latin minuere. Related: Diminished; diminishes; diminishing.

late 13c., from Old French disner (Modern French dîner) "to dine, eat, have a meal," originally "take the first meal of the day," from stem of Gallo-Roman *desjunare "to break one's fast," from Vulgar Latin *disjejunare, from dis- "undo" (see dis-) + Late Latin jejunare "to fast," from Latin iejunus "fasting, hungry" (see jejune).

"one who dines, 1815," agent noun from dine. Meaning "railway car for eating" is 1890, American English; of restaurants built to resemble dining cars (or in some cases actual converted dining cars) from 1935. The Diner's Club credit card system dates from 1952.